console.log(module.exports===exports);
const circle=require("./08_commonjs_circle");
console.log(`圆的面积${circle.area(4)}`);

const circle_area=require("./08_commonjs_circle").area;
console.log(`圆的面积${circle_area(3)}`)


const square=require("./08_commonjs_square");
console.log(`矩形面积${square.area(3)}`)